Apparatus and method for parahydrogen concentration analysis

Abstract

An apparatus and method for parahydrogen concentration analysis may include forming a synthesis gas that may simulate a hydrogen fluid (e.g., a gas or liquid) having 0 mole percent (mol%) parahydrogen. The analyzer may then be calibrated via the use of reference hydrogen having a first preselected parahydrogen concentration (e.g., 25 mol% parahydrogen content) and the synthesis gas to identify a plurality of calibration points of the analyzer for calibrating the analyzer. After the analyzer is calibrated, it may then be used to determine the parahydrogen concentration of one or more hydrogen fluid samples. Some embodiments may be used to help ensure that liquid hydrogen produced via liquefaction or other liquid hydrogen production processes has a parahydrogen content of at least 95 mol%.

Description

Technical Field

[0001] This innovation relates to methods and apparatus for analyzing hydrogen fluids (e.g., liquid hydrogen, hydrogen gas, etc.) to determine the concentration of secondary hydrogen in the hydrogen. Background Technology

[0002] Conventional methods for assessing the concentrations of secondary and normal hydrogen in hydrogen fluids typically involve using an analyzer that is calibrated by passing gas through a catalyst tube to adjust the secondary hydrogen content of the fluid, and then distributing the secondary hydrogen concentration to the gas for analysis by the analyzer.

[0003] Examples of methods for the analysis of secondary and / or orthohydrogen can be found in Japanese Patent No. JP 6327656. Other methods may include the use of nuclear magnetic moment difference, as disclosed in Chinese Patent No. CN104730141. Summary of the Invention

[0004] I have identified several drawbacks in conventional methods for calibrating analytical equipment used to assess the secondary hydrogen content in hydrogen fluids (e.g., liquid hydrogen). For example, in many methods that utilize catalytic tube methods to adjust the concentration of secondary hydrogen in the gas to be used for calibration purposes, it is often impossible to determine whether the hydrogen is at 100% equilibrium at a given temperature, or whether a certain percentage is close to complete equilibrium. The effectiveness of catalytic methods often depends on periodic reactivation, and plant designs for hydrogen production can utilize different target conversions (e.g., target conversions of secondary hydrogen below 100 mol%).

[0005] Furthermore, I have determined that the actual secondary hydrogen content is a strong function of temperature, and in catalyst tube-based methods, the temperature of the calibration gas used may be unknown. For example, the supercooling of liquid hydrogen may be a variable, and there may not be sufficiently accurate known temperature measurements to determine the secondary hydrogen content based on a specific temperature.

[0006] These types of problems can be particularly problematic for analyzers that rely on thermal conductivity-based detection schemes to determine the concentration of secondary and / or primary hydrogen in hydrogen samples. Typically, these devices may depend on predefined calibration curves or schemes. If one of the calibration gas reference points is incorrect, this can significantly affect the accuracy of the analyzer's output for a particular sample. This type of problem can be especially severe in cases requiring precise and accurate determination of the secondary hydrogen content in a hydrogen fluid (e.g., for the certification of liquid hydrogen potentially supplied for aerospace applications, for providing liquid hydrogen as fuel for rocket launches or other aerospace-related uses, etc.).

[0007] I have been surprised to find that current methods used routinely to analyze secondary hydrogen content often fail to address the degree to which secondary equilibrium is reached or the temperature of the liquid H2 in this calibration fluid source. These methods fail to utilize any recognized standard reference and instead simply determine an assumed secondary hydrogen concentration. This is not an accurate second calibration point for calibrating the analyzer. I do not believe this type of problem is even considered routine, as routine methods are generally considered appropriate and accurate.

[0008] Furthermore, utilizing catalyst-based methods can lead to substantial capital and operational costs, which can limit operations. For example, the cost of the liquid hydrogen assembly, including the catalyst tube, can add tens of thousands of dollars to the cost of any potentially usable secondary hydrogen analysis scheme. Additionally, the use of catalyst tubes results in significant maintenance work and costs (e.g., replacement of expensive catalyst materials, catalyst regeneration, etc.). These types of issues add operational complexity and financial costs to liquid hydrogen analysis systems, while simultaneously hindering the achievement of the ambiguous calibration standards required to demonstrate the secondary hydrogen content of the hydrogen produced as a product to consumers.

[0009] I have developed new process and equipment solutions to provide different methods for the analysis of secondary hydrogen content. These solutions offer improved operational flexibility, reduced time required for calibrating analyzer equipment, decreased maintenance needs, avoidance of more expensive catalyst tube-based equipment, and a more reliable method for calibration using a calibration reference fluid that enables more accurate measurements of secondary hydrogen concentration.

[0010] In some embodiments, multi-point calibration can be utilized, which includes the use of a first calibration fluid. This first calibration fluid can be generated to be used as a synthesized 0 mol% p-H2 hydrogen fluid composition (e.g., a fluid simulating 0 mol% p-H2 hydrogen gas). The fluid that can simulate 0 mol% p-H2 hydrogen gas can be, for example, a gas mixture comprising hydrogen mixed with at least one other gas, such that the thermal conductivity of the gas is the same as or substantially similar to that of 0 mol% p-H2 hydrogen gas. As another example, the fluid that can simulate 0 mol% p-H2 hydrogen gas can be, for example, a gas mixture comprising liquid hydrogen mixed with at least one other gas (e.g., helium, krypton, etc.), such that the thermal conductivity of the gas is the same as or substantially similar to that of 0 mol% p-H2 hydrogen gas.

[0011] Multi-point calibration can also utilize a second calibration fluid, which can be considered a "spanfluid". For example, the second calibration fluid could be a room-temperature hydrogen fluid known to be at a defined secondary hydrogen (p-H2) concentration of 25%. This second calibration fluid could be, for example, 25 mol% p-H2 hydrogen stored in a storage container (e.g., a cylinder). In some embodiments, the second calibration fluid can be considered a "spanfluid gas".

[0012] Some implementations can utilize an analyzer configured as a thermal conductivity analyzer. For example, calibration of the thermal conductivity analyzer can be provided using a first calibration fluid and a second calibration fluid (e.g., synthetic 0 mol% p-H2 gas and 25 mol% p-H2 gas, another type of p-H2 content hydrogen fluid and synthetic 0 mol% p-H2 fluid, etc.) to set the analyzer's calibration slope to enable the measurement of the p-H2 value of a sample obtained from produced liquid hydrogen, allowing the calibration slope to be extrapolated more accurately to a 100% p-H2 concentration. I also conducted experiments that helped confirm that the accuracy of this different type of calibration technique can be reliable and provided in a precise manner. My experimental results indicate that implementations can provide accurate determination of secondary hydrogen concentrations, involving lower cost and more flexible calibration procedures.

[0013] Furthermore, I have found that some implementations of my equipment and process can utilize conventional analyzer equipment (e.g., thermal conductivity analyzers available from Teledyne Analytical Instruments, etc.), which allows the implementations to be utilized more easily and efficiently, and at a lower operating and capital cost, compared to conventional methods. The implementations can provide faster, more efficient, and more reliable calibration, which can facilitate improved and more reliable analysis of the concentrations of secondary and / or primary hydrogen in hydrogen fluids, while also providing these characteristics at a lower operating and capital cost.

[0014] In a first aspect, a method for analyzing secondary hydrogen concentration can be provided. This method may include generating a syngas to produce a hydrogen fluid simulating a 0 mol% secondary hydrogen content, such that the syngas has a thermal conductivity equivalent to that of a hydrogen fluid with a 0 mol% secondary hydrogen content; and calibrating the analyzer using the syngas as a first calibration fluid and a second calibration fluid during analyzer calibration. After analyzer calibration, a reference gas may be supplied to the analyzer, and a sample fluid of hydrogen fluid may be supplied to the analyzer for determining the secondary hydrogen content and / or the orthohydrogen content of the sample.

[0015] In some embodiments, the method may be a method for calibrating an analyzer used for secondary hydrogen concentration analysis. In such embodiments, the method may include generating a syngas to produce a hydrogen fluid with a simulated 0 mol% secondary hydrogen content, such that the syngas has a thermal conductivity equivalent to that of a hydrogen fluid with a 0 mol% secondary hydrogen content; and using the syngas as a first calibration fluid and a second calibration fluid to calibrate the analyzer during calibration. The calibrated analyzer can then be used to evaluate one or more hydrogen fluid samples to determine the secondary hydrogen content and / or the orthohydrogen content of the samples.

[0016] In some implementations, the analyzer may be a thermal conductivity analyzer. Alternatively, the analyzer may be another suitable type of analyzer.

[0017] The thermal conductivity of a synthesis gas can be equated to the thermal conductivity of a hydrogen fluid with a secondary hydrogen content of 0 mol% by having a thermal conductivity equal to that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. The thermal conductivity of a synthesis gas can also be equated to the thermal conductivity of a hydrogen fluid with a secondary hydrogen content of 0 mol% by having a thermal conductivity within 1% of that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. The thermal conductivity of a synthesis gas can also be equated to the thermal conductivity of a hydrogen fluid with a secondary hydrogen content of 0 mol% by having a thermal conductivity within 0.5% of that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. The thermal conductivity of a synthesis gas can also be equated to the thermal conductivity of a hydrogen fluid with a secondary hydrogen content of 0 mol% by having a thermal conductivity within 0.1% of that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. As yet another example, the thermal conductivity of a synthesis gas can also be equivalent to that of a hydrogen fluid with a thermal conductivity of 0 mol% secondary hydrogen content by means of a synthesis gas having a thermal conductivity of less than 0.01% of that of a hydrogen fluid with a thermal conductivity of 0 mol% secondary hydrogen content.

[0018] In a second aspect, the generation of the synthesis gas may include mixing hydrogen gas with a secondary hydrogen content of 25 mol% with helium gas to form a synthesis gas, such that the synthesis gas has a helium content between 0.5 mol% and 4 mol% helium, and the balance of the synthesis gas is hydrogen gas with a secondary hydrogen content of 25 mol%. For example, in some embodiments, the helium content of the synthesis gas may be between 1.15 mol% and 1.30 mol% helium. In other embodiments, the helium content of the synthesis gas may be between 1.17 mol% and 1.27 mol% helium.

[0019] In a third aspect, the generation of the synthesis gas may include mixing hydrogen gas with a secondary hydrogen content of 25 mol% with at least one additive fluid to form the synthesis gas. In some embodiments, the at least one additive fluid may include one or more of nitrogen, krypton, argon, helium, or combinations thereof.

[0020] In a fourth aspect, the generation of the synthesis gas may include mixing hydrogen with at least one additive fluid to form the synthesis gas. The at least one additive fluid may be mixed with hydrogen such that the resulting synthesis gas has a thermal conductivity equivalent to that of a hydrogen fluid having a secondary hydrogen content of 0 mol%

[0021] In a fifth aspect, a method for performing calibration of secondary hydrogen concentration analysis can be provided. The method may include generating a syngas simulating a hydrogen fluid with a secondary hydrogen content of 0 mol% such that the thermal conductivity of the syngas is equivalent to that of a hydrogen fluid with a secondary hydrogen content of 0 mol%; and using the syngas as a first calibration fluid and a second calibration fluid to calibrate the analyzer.

[0022] In some implementations, using syngas as both a first and second calibration fluid to calibrate the analyzer may include supplying the analyzer with the first calibration fluid and a reference fluid for supplying to and / or passing through the analyzer's measurement cell during a pre-selected equilibration period to establish a first calibration data point for the analyzer. After establishing the first calibration point on the analyzer using the first calibration fluid, the supply of the first calibration fluid to the analyzer may be stopped, and subsequently, the second calibration fluid and the reference fluid may be supplied to the analyzer during a pre-selected equilibration period to establish a second calibration data point for the analyzer.

[0023] Using synthesis gas as the first and second calibration fluids to calibrate the analyzer may further include inputting an input into the analyzer to define the secondary hydrogen content of 0 mol% secondary hydrogen for the first calibration fluid, while supplying the first calibration fluid to the analyzer to establish a first calibration data point; and inputting an input into the analyzer to define the secondary hydrogen content of the second calibration fluid, while supplying the second calibration fluid to the analyzer to establish a second calibration data point.

[0024] In some embodiments, the second calibration fluid has a secondary hydrogen content of 25 mol% and is hydrogen gas. In other embodiments, the second calibration fluid may be hydrogen gas with another pre-selected secondary hydrogen concentration.

[0025] As discussed above, the generation of syngas may include mixing hydrogen gas with a secondary hydrogen content of 25 mol% with at least one additive fluid to form syngas. The at least one additive fluid may include one or more of nitrogen, krypton, argon, helium, or combinations thereof. In some embodiments, the helium content of the syngas may be between 1.15 mol% and 1.30 mol% helium, or between 1.17 mol% and 1.27 mol% helium.

[0026] In the sixth aspect, the methods of the first or fifth aspects may include other features or elements. Examples of such features or elements can be understood from exemplary embodiments of the methods discussed herein and / or illustrated in the accompanying drawings. Embodiments of the method may also utilize elements of an apparatus for secondary hydrogen concentration analysis.

[0027] In a seventh aspect, an apparatus for analyzing secondary hydrogen concentration is provided. One embodiment of the apparatus can be configured to implement an embodiment of a method for calibrating an analyzer and / or an embodiment of a method for analyzing secondary hydrogen concentration. The embodiment of the apparatus may include an analyzer, a reference gas source fluidly connected to the analyzer, a first calibration gas source fluidly connected to the analyzer, and a second calibration fluid source containing hydrogen fluid fluidly connected to the analyzer. The first calibration gas may be a synthesis gas having a certain content of hydrogen and at least one additive fluid to simulate a hydrogen fluid with a 0 mol% secondary hydrogen content, such that the synthesis gas has a thermal conductivity equivalent to that of a hydrogen fluid with a 0 mol% secondary hydrogen content.

[0028] As described above, in some embodiments, the analyzer may be a thermal conductivity analyzer. Alternatively, the analyzer may be another suitable type of analyzer.

[0029] As mentioned above, the thermal conductivity of a synthesis gas can be equivalent to that of a hydrogen fluid with a secondary hydrogen content of 0 mol% by having a thermal conductivity equal to that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. The thermal conductivity of a synthesis gas can also be equivalent to that of a hydrogen fluid with a secondary hydrogen content of 0 mol% by having a thermal conductivity within 1% of that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. The thermal conductivity of a synthesis gas can also be equivalent to that of a hydrogen fluid with a secondary hydrogen content of 0 mol% by having a thermal conductivity within 0.5% of that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. The thermal conductivity of a synthesis gas can also be equivalent to that of a hydrogen fluid with a secondary hydrogen content of 0 mol% by having a thermal conductivity within 0.1% of that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. As yet another example, the thermal conductivity of a synthesis gas can also be equivalent to that of a hydrogen fluid with a thermal conductivity of 0 mol% secondary hydrogen content by means of a synthesis gas having a thermal conductivity of less than 0.01% of that of a hydrogen fluid with a thermal conductivity of 0 mol% secondary hydrogen content.

[0030] The reference gas source, the first calibration fluid source, and the second calibration fluid source may include storage containers, storage vessels, or arrays of such storage containers or vessels. For example, each source may include one or more gas cylinders or other types of fluid storage tanks.

[0031] In the eighth aspect, embodiments of the device may include other features or other elements. Examples of such features and / or elements may include features or elements of the exemplary embodiments discussed herein and / or illustrated in the accompanying drawings.

[0032] It should be understood that implementations of this method and apparatus can utilize a variety of conduit arrangements and process control elements. These implementations can utilize sensors (e.g., pressure sensors, temperature sensors, flow rate sensors, concentration sensors, etc.), controllers, valves, piping, and other process control elements. For example, some implementations can utilize automated process control systems and / or distributed control systems (DCS). A wide variety of conduit arrangements and process control systems can be used to meet a specific set of design criteria.

[0033] Further details, objectives, and advantages of the apparatus for secondary hydrogen concentration analysis, the method for secondary hydrogen concentration analysis, the method for performing calibration of the secondary hydrogen concentration analysis, the method for forming a syngas simulating 0 mol% secondary hydrogen content, and the methods of manufacturing and using thereof will become apparent as a result of the following description of certain exemplary embodiments. Attached Figure Description

[0034] Exemplary embodiments of our apparatus for secondary hydrogen concentration analysis, methods for secondary hydrogen concentration analysis, methods for performing calibration for secondary hydrogen concentration analysis, methods for generating a syngas simulating 0 mol% secondary hydrogen content, and methods for manufacturing and using thereof are shown in the accompanying drawings. It should be understood that the same reference characters used in the drawings may identify the same parts.

[0035] Figure 1 This is a block diagram of a first exemplary embodiment of a device for analyzing secondary hydrogen concentration. From Figure 1 Exemplary implementations of methods for analyzing secondary hydrogen concentrations can also be understood.

[0036] Figure 2 This is a block diagram of an exemplary embodiment of a tan analyzer 6, which can be used for... Figure 1 An exemplary implementation of the apparatus for analyzing secondary hydrogen concentration shown.

[0037] Figure 3 It is a graph showing the equilibrium curves of secondary hydrogen concentration at different temperatures in the range of 0 Kelvin to 300 Kelvin (K).

[0038] Figure 4 This is a flowchart illustrating an exemplary embodiment of a method for analyzing the concentration of secondary hydrogens. The method can also utilize an exemplary embodiment of a method for performing calibration of the secondary hydrogen concentration analysis. A first exemplary embodiment of a device for analyzing the secondary hydrogen concentration can implement these exemplary embodiments of the methods.

[0039] Figure 5 This is a schematic illustration of an exemplary embodiment of a method for forming a syngas with a simulated 0 mol% secondary hydrogen content. Detailed Implementation

[0040] refer to Figures 1 to 5 The apparatus 1 for secondary hydrogen concentration analysis may include an analyzer 6, which is positioned to receive a first reference fluid from a first reference gas source 3, and (i) a sample gas from a sample fluid source 7, (ii) a first calibration fluid source 5a, or (iii) a second calibration fluid source 5b. For example, the first calibration fluid source 5a may be at least one storage vessel (e.g., a gas cylinder or other pressurized storage vessel) holding 0 mol% of synthesized secondary hydrogen gas. For example, the second calibration fluid source 5b may be at least one storage vessel (e.g., a gas cylinder or other pressurized storage vessel) holding 0 mol% of synthesized secondary hydrogen gas. For example, the first reference fluid source 3 may be at least one storage vessel (e.g., a gas cylinder or other pressurized storage vessel) holding a reference gas, such as 25 mol% p-H2 hydrogen.

[0041] The sample fluid source 7 may include at least one storage vessel (e.g., a gas cylinder or other pressurized storage vessel) that holds hydrogen gas from the sample, derived from liquid hydrogen produced from a liquid hydrogen production facility (e.g., a hydrogen liquefaction unit, hydrogen liquefaction system, etc.). In some embodiments, a manifold may be connected between the sample gas source 7 and the analyzer 6, allowing fluid from different storage vessels to be supplied to the analyzer 6 for faster and easier analysis. In some configurations, a first calibration fluid source 5a and a second calibration fluid source 5b may also be fluidly connected to such a manifold.

[0042] A conduit arrangement 4 can be provided to fluidly connect the analyzer 6 to different fluid sources. A manifold (not shown) can be provided as part of the conduit arrangement, allowing multiple different sample storage containers to be fluidly connected to the analyzer, providing a faster process for adjusting which sample fluid is supplied to the analyzer for analysis.

[0043] For example, the conduit assembly 4 may include a reference fluid supply conduit 4a positioned to fluidly connect a reference fluid source 3 to a reference fluid evaluation chamber 6b located within the housing 6a of the analyzer 6. In some embodiments, the reference fluid supply conduit 4a may include a valve V adjustable between a closed position and an open position. The conduit assembly may also include a fluid analysis supply conduit 4b fluidly connected to a contrast fluid evaluation chamber 6c located within the housing 6a of the analyzer.

[0044] The fluid analysis supply conduit 4b may include a flow meter or other sensor for determining the flow rate of fluid supplied via the fluid analysis supply conduit 4b to the comparison fluid evaluation chamber 6c. The reference fluid supply conduit 4a may also include a flow meter or other sensor for determining the flow rate of fluid supplied via the reference fluid supply conduit 4b to the reference fluid evaluation chamber 6b. These flow meter sensors may be communicatively connected to the computer device CD of the analyzer 6 for evaluating data obtained by at least one sensing element 6d, which is operatively connected to both the comparison fluid evaluation chamber 6c and the reference fluid evaluation chamber 6b. One or more sensing elements 6d may be communicatively connected to the computer device CD of the analyzer 6 via a communication connection CC for providing the data to the computer device CD.

[0045] For example, at least one sensing element 6d can be positioned between a contrast fluid evaluation chamber 6c and a reference fluid evaluation chamber 6b to sense at least one parameter associated with the fluid passing through the contrast fluid evaluation chamber 6c, and how that fluid may differ from a reference fluid passing through the reference fluid evaluation chamber 6b. During this evaluation, the temperatures of the two chambers can also be maintained at substantially the same temperature (e.g., within 0.1°C or 0.5°C of each other) to help facilitate accurate parameter sensing. Temperature sensors can be positioned to detect the temperature of the different chambers (which may also be referred to as measurement units) for monitoring and controlling the temperatures of these chambers.

[0046] For example, the detectable parameter could be a change in resistance, either voltage or current, which could be provided via resistors positioned in the comparison fluid evaluation chamber 6c and the reference fluid evaluation chamber 6b. Data on such resistance changes could be used by a computer device CD to assess how the thermal conductivity of the fluid passing through the comparison fluid evaluation chamber 6c differs from that of the fluid passing through the reference fluid evaluation chamber 6b, in order to determine the secondary hydrogen content of the fluid passing through the comparison fluid evaluation chamber 6c.

[0047] For example, in some embodiments, the sensing element 6d may include at least one Wheatstone bridge circuit. As the reference fluid and the control fluid being analyzed pass through their respective chambers, the bridge may become unbalanced, causing current to flow in the detector circuit. The amount of this current may be an indication of the type of gas or the concentration of positive and / or negative hydrogen in the gas.

[0048] After the reference fluid passes through the reference fluid chamber 6b, it can be discharged or otherwise output via the reference fluid outlet conduit 6o, which is fluidly connected to the reference fluid chamber 6b. After the comparison fluid passes through the comparison fluid evaluation chamber, the fluid can also be output from the comparison fluid evaluation chamber 6c via the fluid outlet conduit 6o, which is fluidly connected to the comparison fluid evaluation chamber 6c, for discharge or other processing downstream of the analyzer 6.

[0049] As described above, in some embodiments, the analyzer 6 may be configured such that at least one sensing element 6d provides data relating to the difference in thermal conductivity between a reference fluid passing through a reference fluid evaluation chamber 6b and the fluid to be analyzed passing through a contrast fluid evaluation chamber 6c. The analyzer 6 may include a computer device CD connected to at least one sensing element 6d to receive data and determine the content of the sample fluid based on the data (e.g., voltage or current that may pass through the detection circuitry of the sensing element, etc.), calibration data, and a predefined thermal conductivity analysis method defined by code stored in the memory of the analyzer 6, the processor of the computer device CD of the analyzer being able to execute the predefined thermal conductivity analysis method.

[0050] In some implementations, analyzer 6 may be or may include a thermal conductivity orthohydrogen / parahydrogen analyzer (e.g., a Teledyne 2000 orthohydrogen / parahydrogen analyzer, a 2000A-EU thermal conductivity analyzer provided by Teledyne Analytical Instruments, or a similar type of analyzer).

[0051] The conduit assembly 4 may also include a valve V to facilitate control of the fluid supplied to the analyzer 6. For example, the conduit assembly may include a sample supply conduit 4c fluidly connected to the fluid analysis supply conduit 4b for supplying fluid from the sample fluid source 7 to the contrast fluid evaluation chamber 6c. The sample supply conduit 4c may include a valve V adjustable between an open and closed position to supply sample fluid from the sample fluid source 7 to the contrast fluid evaluation chamber 6c of the analyzer 6, or to prevent the supply of fluid to the analyzer 6.

[0052] The conduit assembly may include a first calibration fluid supply conduit 4d, which is fluidly connected to a fluid analysis supply conduit 4b for supplying fluid from a first calibration fluid source 5a to a contrast fluid evaluation chamber 6c. The first calibration fluid supply conduit 4d may include a valve V adjustable between an open and closed position to supply the first calibration fluid from the first calibration fluid source 5a to the contrast fluid evaluation chamber 6c of the analyzer 6, or to prevent the supply of fluid to the analyzer 6.

[0053] The conduit assembly may include a second calibration fluid supply conduit 4e, which is fluidly connected to the fluid analysis supply conduit 4b for supplying fluid from a second calibration fluid source 5b to a contrast fluid evaluation chamber 6c. The second calibration fluid supply conduit 4e may include a valve V adjustable between an open and closed position to supply the second calibration fluid from the second calibration fluid source 5b to the contrast fluid evaluation chamber 6c of the analyzer 6, or to prevent the supply of fluid to the analyzer 6.

[0054] In some embodiments, the first reference fluid and the second calibration fluid can be the same type of fluid. For example, in some embodiments, the first reference fluid can be 25 mol% pH₂ hydrogen stored in a storage vessel (e.g., a gas cylinder), which has been stored at room temperature for a sufficient period of time to reach equilibrium and is at a known concentration of 25 mol% pH₂ in hydrogen. The second calibration fluid can also be 25 mol% pH₂ hydrogen stored in a storage vessel (e.g., a gas cylinder). In some embodiments, the second calibration fluid can be hydrogen that has been stored at room temperature for a sufficient period of time to reach equilibrium and is at a known concentration of 25 mol% pH₂ in hydrogen.

[0055] The sample fluid from at least one sample fluid source 7 may be hydrogen fluid obtained from one or more production runs of a hydrogen liquefaction system or other hydrogen production system. For example, in some embodiments, the sample fluid may be obtained from produced liquid hydrogen, which is then heated into a gas. Each sample fluid source 7 may be a vessel or other type of storage container or group of storage containers that can retain the sample fluid for supply to the analyzer 6 via the conduit device 4.

[0056] The second calibration fluid stored in the second calibration fluid source 5b can be stored in at least one storage vessel or other type of storage container, which can be fluidly connected to the analyzer 6 via conduit 4. The first reference fluid stored in the first reference fluid source 3 can be stored in at least one storage vessel or other type of storage container, which can be fluidly connected to the analyzer 6 via conduit 4.

[0057] The first calibration fluid may be a synthesis gas, which is formed to simulate the thermal conductivity of hydrogen with a p-H2 content of 0 mol%. This synthesis gas may be formed and subsequently stored in at least one storage vessel or other storage container, which is fluidly connected to the analyzer 6 via a conduit device 4.

[0058] The formation of a synthesis gas that can be provided as a first calibration fluid may include mixing at least one thermally conductive additive fluid with 25 mol% p-H2 hydrogen (e.g., hydrogen that has been stored at room temperature to achieve an equilibrium of 25 mol% p-H2, for example, from...). Figure 3 (Understandably) Mixed to provide a synthesis gas having the same or substantially similar thermal conductivity as 0 mol% p-H2 hydrogen (e.g., within 5% of the thermal conductivity of 0 mol% p-H2 hydrogen). Figure 5 An exemplary method for generating synthesis gas is shown.

[0059] As from Figure 5As best seen in the diagram, hydrogen (e.g., 25 mol% p-H2 hydrogen) can be supplied to a mixing device along with at least one additive fluid. The mixing device can be an inline mixer, a mixing vessel, or other type of mixing mechanism that can mix fluids together. The mixed fluid can be output from the mixing device and supplied to at least one storage vessel (e.g., at least one gas cylinder, at least one storage container, etc.) for storing the formed synthesis gas. Mixing can be performed such that the additive fluid is added to the hydrogen, resulting in a synthesis gas having a thermal conductivity equivalent to that of hydrogen with a 0 mol% secondary hydrogen content (e.g., the thermal conductivity of the synthesis gas can be equal to, or within, a predetermined tolerance of, that of hydrogen with a 0 mol% secondary hydrogen content). For example, the formed synthesis gas can have a thermal conductivity within 0.1% or 0.01% of the thermal conductivity of hydrogen with a 0 mol% secondary hydrogen content. As another example, the resulting synthesis gas can have a thermal conductivity within 1% or 0.5% of the thermal conductivity of hydrogen with a secondary hydrogen content of 0 mol%.

[0060] For example, in some embodiments, the syngas of the first calibration fluid simulating the thermal conductivity of 0 mol% p-H2 hydrogen can be formed by mixing helium, as a thermally conductive additive fluid, with room-temperature hydrogen that has been stored at room temperature sufficiently to reach equilibrium, such that the hydrogen is 25 mol% p-H2 hydrogen, to form a syngas simulating the thermal conductivity of 0 mol% p-H2 hydrogen. In some embodiments, helium can be mixed with hydrogen such that the formed syngas has 0.5 mol% helium to 4 mol% helium. For example, embodiments may mix helium with hydrogen to provide a syngas between 1 mol% helium and 2 mol% helium, with the balance being 25 mol% p-H2 hydrogen. In some embodiments, the syngas has been formed to provide a helium concentration between 1.15 mol% and 1.30 mol% (e.g., 1.17 mol% helium, 1.19 mol% helium, 1.20 mol% helium, 1.23 mol% helium, 1.25 mol% helium, 1.27 mol% helium, etc.). In other embodiments, the synthesis gas has been formulated to provide a helium concentration between 1.17 mol% and 1.27 mol% (e.g., 1.17 mol% helium, 1.18 mol% helium, 1.19 mol% helium, 1.20 mol% helium, 1.23 mol% helium, 1.24 mol% helium, 1.246 mol% helium, 1.25 mol% helium, 1.26 mol% helium, etc.).

[0061] In other embodiments, a synthesis gas may be used, which is mixed with hydrogen using different thermally conductive additive fluids, or different combinations of thermally conductive additive fluids, to form a synthesis gas with a thermal conductivity simulating that of 0 mol% p-H2 hydrogen. For example, the thermally conductive additive fluid may include, for example, nitrogen, krypton, argon, helium, or a combination of two or more of these gases. As yet another example, the thermally conductive additive fluid may include another suitable additive fluid for mixing with 25 mol% p-H2 hydrogen to form a first calibration fluid synthesis gas having the same or substantially similar thermal conductivity as 0 mol% p-H2 hydrogen (e.g., within 5% of the thermal conductivity of 0 mol% p-H2 hydrogen, within 1% of the thermal conductivity of 0 mol% p-H2 hydrogen, within 0.5% of the thermal conductivity of 0 mol% p-H2 hydrogen, within 0.1% of the thermal conductivity of 0 mol% p-H2 hydrogen, etc.).

[0062] The apparatus 1 for secondary hydrogen concentration analysis can be used to calibrate the analyzer 6 by using a first calibration fluid, a second calibration fluid, and a reference fluid, and then, after the analyzer 6 has been calibrated for a pre-selected period of time or a pre-selected number of analyses, before the analyzer 6 can be calibrated again, analyze one or more samples in a continuous or sequential manner.

[0063] exist Figure 3 An example of a method for calibrating analyzer 6 and subsequently evaluating the secondary hydrogen content and / or orthohydrogen content of a hydrogen fluid sample is shown. In the first step S1, a synthesis gas can be generated having a thermal conductivity that simulates that of 0 mol% p-H2 hydrogen. As discussed above, this synthesis gas can be formed to be used as a first calibration fluid stored in a first calibration fluid source 5a (e.g., a storage vessel for storing the synthesis gas). As described above, the synthesis gas can be formed by mixing 25 mol% p-H2 hydrogen with at least one other gas to form a synthesis gas having the same or substantially similar thermal conductivity as 0 mol% secondary hydrogen.

[0064] In the second step S2, analyzer 6 can be calibrated. This calibration may involve providing a first calibration point for analyzer 6 by passing a reference gas through a reference gas evaluation chamber 6b and a first calibration fluid (e.g., a synthesis gas simulating 0 mol% p-H2 hydrogen) through a control fluid evaluation chamber 6c. This can be provided by closing valve V of the sample supply conduit 4c and the second calibration fluid conduit 4e and opening valve V of the first calibration fluid conduit 4d, so that the first calibration fluid from the first calibration fluid source 5a can be supplied to analyzer 6. This supply of the first calibration fluid and the reference fluid to analyzer 6 for use in supplying and / or passing through the measurement units of analyzer 6 (e.g., reference fluid evaluation chamber 6b and control fluid evaluation chamber 6c) can occur within a pre-selected equilibration period to help ensure that the fluids within the chambers are in equilibrium, thereby helping to provide accurate analysis via analyzer 6. The analyzer 6 can be provided with input via an input device (e.g., a button on the analyzer's user interface, a computer interface provided for communication with the analyzer 6's computer device, etc.) to set its calibration, thereby confirming that the first calibration fluid is a fluid with 0 mol% p-H2 hydrogen for hydrogen gas.

[0065] After setting a first calibration point on the analyzer using the first calibration fluid, the supply of the first calibration fluid to the analyzer 6 can be stopped, and then a second calibration fluid can be supplied to the analyzer to provide a second calibration data point. For example, valve V for the sample supply conduit 4c and the first calibration fluid conduit 4d can be closed, and valve V for the second calibration fluid conduit 4e can be opened, allowing the second calibration fluid from the second calibration fluid source 5b to be supplied to the analyzer 6. This supply of the second calibration fluid and reference fluid to the analyzer 6 for use in supplying and / or passing through the measurement units of the analyzer 6 (e.g., reference fluid evaluation chamber 6b and control fluid evaluation chamber 6c) can occur within a pre-selected equilibration period to help ensure that the fluids in the chambers are in equilibrium, thereby helping to provide accurate analysis via the analyzer 6. The analyzer 6 can then be provided with input via an input device (e.g., buttons on the analyzer's user interface, a computer interface provided for communication with the analyzer 6's computer device, etc.) to set its calibration, thereby confirming that this second calibration fluid is a fluid with a hydrogen concentration of 25 mol% p-H2.

[0066] This calibration, using synthesis gas as 0 mol% p-H2 hydrogen and another calibration fluid (e.g., 25 mol% p-H2 hydrogen), helps establish multiple calibration points for the analyzer's secondary hydrogen concentration detection analysis (e.g., setting a first and second calibration point for the analyzer's use in evaluating sample fluids via its predefined analytical scheme). This allows for a more accurate assessment of the secondary hydrogen content in the sample, which helps ensure that for secondary hydrogen contents of 95 mol% or less, the secondary hydrogen content in the sample is detected with improved accuracy, thus helping to more accurately and reliably detect samples with hydrogen contents of 95 mol% or higher. I have found that an implementation scheme can be provided that allows the analyzer 6 to have a significantly higher degree of determinism, i.e., after calibration using this second step S2, the sample analyzed has a hydrogen content higher than 95 mol% p-H2. The implementation scheme can be used to help better detect hydrogen fluids with a secondary hydrogen content below 95 mol%, indicating that such products may not meet certain secondary hydrogen content specifications that require a secondary hydrogen content of more than 95 mol%, and can also provide more reliable certification for hydrogen products with a secondary hydrogen content above 95 mol%.

[0067] Furthermore, I have found that this type of calibration method can provide a faster, simpler, and less costly approach to calibration. For example, the implementation can be utilized in any situation where expensive catalyst tube equipment is not required. Moreover, experiments have shown that using a synthesis fluid that can simulate the thermal conductivity of 0 mol% pH-H2 hydrogen provides an effective and reliable method for analyzing the pH-H2 content of hydrogen samples obtained from liquid hydrogen production facilities or from one or more liquid hydrogen storage and / or transport trailers. This lower cost—in both capital and operating costs—along with the increased simplicity and improved operational flexibility (e.g., the elimination of the need to address issues related to the activity of the catalyst or its potential changes during use, such as the catalyst becoming poisoned or clogged during use and requiring regeneration or replacement, or difficulties arising from not knowing the extent to which hydrogen has reached its secondary hydrogen equilibrium, or the temperature at which the stored liquid hydrogen can determine the equilibrium pH-H2 concentration value), helps provide improved operational efficiency and reliability. Furthermore, I have found that the implementation scheme can allow for more accurate and reliable certification of the secondary hydrogen content in liquid hydrogen produced for aerospace and other applications, where high secondary hydrogen content specifications (e.g., at least 95 mol% p-H2 secondary hydrogen content in liquid hydrogen or hydrogen gas) may be a requirement for at least some aerospace industry customers.

[0068] After the analyzer 6 is calibrated, at least one sample from at least one sample source 7 can be supplied to the analyzer for analysis of the secondary hydrogen content and / or orthohydrogen content of the sample in the third step S3. Each sample used in the analysis can be a sample from a liquid hydrogen production operation that produces liquid hydrogen to help determine the secondary hydrogen content of the hydrogen.

[0069] For example, after the calibration of analyzer 6 is completed, reference fluid and sample fluid can be supplied to analyzer 6 to determine the secondary hydrogen content and / or orthohydrogen content of a sample (e.g., a sample of liquid hydrogen that has recently evaporated to a gaseous state for analysis). This can be provided by closing valve V for the first calibration fluid conduit 4d and the second calibration fluid conduit 4e and opening valve V for the sample fluid conduit 4c, so that sample fluid from sample fluid source 7 can be supplied to analyzer 6. This supply of sample fluid and reference fluid to analyzer 6 for supply to and / or through the measurement units of analyzer 6 (e.g., reference fluid evaluation chamber 6b and contrast fluid evaluation chamber 6c) can occur within a pre-selected equilibration period to help ensure that the fluids in the chambers are in equilibrium, thereby helping to provide accurate analysis via analyzer 6. Analyzer 6 can then measure the difference in thermal conductivity between the sample fluid and the reference fluid to facilitate the determination of the secondary hydrogen content and / or orthohydrogen content of the sample fluid via at least one sensing element 6d, and provide an output indicating the determined content values ​​of the secondary hydrogen content and / or orthohydrogen content of the sample fluid.

[0070] After evaluating the first sample, analyzer 6 can be recalibrated for another evaluation of the sample. Alternatively, initial calibration may be acceptable for multiple evaluations using additional samples. Analyzer 6 can be recalibrated after a pre-selected time period or a predefined number of sample analyses have been performed. In such cases, the second step S2 of the process can be repeated. If a sufficient amount of syngas is not available for calibration, the first step S1 can be performed before the second step S2 to calibrate analyzer 6 for subsequent evaluation of other samples.

[0071] In some embodiments, the computer device CD of the analyzer 6 may be the controller or other computer device of the analyzer 6, configured to receive data from the sensing element 6d and other sensors (e.g., a flow meter sensor for the conduit, a temperature sensor for the measuring unit, etc.) to analyze the secondary hydrogen content and / or the orthohydrogen content of the fluid via a predefined analysis scheme defined in code in the memory of the computer device. The non-transitory memory of the computer device CD may be connected to a processor for executing the code. The computer device may also include at least one interface for communicatively connecting to at least one user interface, which may be disposed on a user interface element and / or user device integrated into the housing 6a. The user device may be communicatively connected to the analyzer's computer device via a network connection (e.g., a LAN connection, a wireless LAN connection, etc.), a wired connection, or a near-field connection (e.g., a Bluetooth connection) via at least one transceiver, which may be communicatively connected to the processor of the computer device CD. The user interface of the analyzer 6, which may be integrated into the housing 6a or otherwise connected to a computer device, may include a display, multiple input elements (e.g., buttons, knobs, keyboards, etc.), and may also be communicatively connected to at least one user device (e.g., a laptop computer, tablet computer, workstation, data server, etc.) for transmitting analytical data generated by the computer device for storage, printing, or other use by an operator device or operator computer system.

[0072] I conducted experimental work to evaluate the implementation of apparatus 1 and the method. In the experimental work conducted, I was able to determine the concentration of an additive gas (e.g., helium) in the hydrogen, which was 25 mol% p-H2 hydrogen, after I was satisfied that the concentration of the additive gas added to the hydrogen to form the syngas was nominally correct. Calibration using the formed syngas provided analyzer readings for samples of liquid hydrogen between 95 mol% p-H2 and 100 mol% p-H2, to help confirm the proof-of-concept implementation of the method and apparatus.

[0073] In other experiments, samples of liquid hydrogen with known pH values ​​can be provided for experimental work by aging the liquid hydrogen stored in tankers or trailers for at least two weeks to help ensure that the hydrogen reaches its equilibrium pH value. Experiments have shown that, by using a first calibration fluid and a second calibration fluid, one of which is a synthesis gas simulating 0 mol% pH H2 hydrogen, analysis of samples calibrated using an analyzer provides a reliable and accurate determination of secondary hydrogen content exceeding 95 mol% in the sample.

[0074] I also conducted experiments altering the mixture of hydrogen and at least one additive gas (e.g., helium) to obtain target pH2 measurements, thus determining that using syngas as a substitute for 0 mol% pH2 gas could provide calibration for analyzer 6, resulting in improved and reliable results when detecting secondary hydrogen content above 25 mol% pH2. I was surprised to find this possible because the thermal conductivity of hydrogen between 0 mol% and 100 mol% secondary hydrogen can be a linear function. The experiments I performed showed that two-point calibration using 0 mol% and 25 mol% pH2 allowed setting a slope in the predefined analytical model used by the analyzer, enabling analyzer 6 to accurately extrapolate to concentrations greater than 95 mol% pH2. The experiments performed have demonstrated that the resulting calibration accurately measures the pH2 content in freshly evaporated liquid hydrogen trailer samples with known pH2 values.

[0075] My experimental work has surprisingly revealed the formation of a syngas composition that has been experimentally proven to provide the thermal conductivity of 0 mol% p-H2 (or 100 mol% positive hydrogen), which does not exist in nature. My apparatus, process, and calibration method implementation can provide better results than conventional catalyst tube-based methods because it does not rely on unverifiable assertions about the secondary hydrogen equilibrium value or the temperature of the liquid hydrogen from which the sample is obtained to determine the p-H2 content.

[0076] For example, in some of the experimental work performed, tankers of liquid hydrogen that had been stored under normal ambient conditions for at least two weeks (sufficient time for the stored liquid hydrogen to reach 100% equilibrium without relying on any catalyst) were used to evaluate implementations of my method and apparatus. The temperature of the stored liquid hydrogen was obtained by measuring the vapor pressure of the liquid in vapor-liquid equilibrium in the tanker. Then, publicly available lookup tables (e.g., based on) were used to determine the secondary hydrogen content of liquid hydrogen at 100% equilibrium at different temperatures. Figure 3 The lookup table shown is used to determine the secondary and orthohydrogen content of liquid hydrogen based on the measured temperature. Then, using an embodiment of the apparatus and method, I calibrated analyzer 6 by using a first calibration fluid and a second calibration fluid (which consisted of 0 mol% and 25 mol% synthesized secondary hydrogen gas as the first and second calibration fluids). After calibration, the analyzer was used to detect the secondary hydrogen content in a sample of liquid hydrogen from a tanker truck to compare the results from the lookup table with those obtained by calibrating analyzer 6. This experimental work further demonstrates that, after calibration using an embodiment of my apparatus via an embodiment of my method, analyzer 6 can accurately and reliably detect the secondary and / or orthohydrogen content of liquid hydrogen samples.

[0077] However, my work involves significant technical difficulties. For example, the precise mixing of additive gases to be included in hydrogen to form the synthesis gas is extremely difficult to identify and generate. For instance, hydrogen may be difficult to purchase from commercial cylinder gas suppliers with sufficient purity to help provide accurate content assessment (e.g., a concentration of hydrogen with + / - 0.01 mol% helium), which is significantly higher purity than that available from suppliers, who typically provide + / - 3 mol% hydrogen and approximately + / - 0.04 mol% helium.

[0078] In conducting this experiment, I determined to utilize a dilution or mixing system, which allows for gas mixing on the analyzer panel to produce a target gas mixture of the desired composition, similar to... Figure 5 The process shown (and also discussed herein) can be a method that, in some cases, can provide better and more reliable results to help achieve the desired syngas formation. The additional cost associated with using such a system is less than $11,000 for providing 1–2 years of calibration support. This is more cost-effective than conventional catalyst-based methods, which can have capital costs exceeding $40,000 and, as discussed herein, also result in significant operating costs, and can provide the improved reliability of secondary hydrogen content assessment work as discussed herein.

[0079] Embodiments of the apparatus, methods, calibration methods for performing secondary hydrogen concentration analysis, and / or methods for generating a syngas simulating 0 mol% secondary hydrogen content can be used in a variety of environmental or industrial applications. For example, in some embodiments, the method and / or apparatus can be used in a laboratory for research purposes. In other embodiments, the method and / or apparatus can be provided in conjunction with hydrogen production to provide certification of the secondary hydrogen content and / or orthohydrogen content of hydrogen produced by one or more different facilities.

[0080] It should also be understood that other modifications can be made to meet a specific set of criteria for different implementations of device 1 or method. For example, the layout of valves, flow meters, temperature sensors, other sensors, pipes, and other conduit components (e.g., conduit connection mechanisms, tubing, seals, valves, etc.) used to interconnect different units of the device for fluid communication between different components can be arranged to meet a specific facility layout design that takes into account the available area of ​​the device, the size configuration of the device, and other design considerations. For example, the size or type of analyzer 6 and other equipment can be modified to meet a specific set of design criteria. As yet another example, each fluid source may include at least one storage vessel or container, or a set of storage vessels or containers, which can be fluidly connected to analyzer 6. The size and type of storage vessels or containers that can be used to calibrate fluid sources and / or sample sources can be any suitable size and configuration of storage devices that can be adapted for a specific set of design criteria for device 1.

[0081] It should also be understood that some embodiments of this method can modulate the calibration process while still using the syngas as the calibration fluid. For example, in some embodiments, the syngas can be used as the second calibration fluid, and a first calibration fluid can be used, which is another hydrogen gas with a different secondary hydrogen content (e.g., the first calibration fluid can be 25 mol% p-H2 hydrogen, and the second calibration fluid can be the syngas). In such embodiments, calibration can be performed such that the first calibration point for the first calibration gas entering the analyzer can be the p-H2 content of that gas (e.g., 25 mol% p-H2 hydrogen), and the second calibration point for the syngas entering the analyzer can be 0 mol% p-H2 content when the syngas is used as the second calibration gas.

[0082] As yet another example, it is contemplated that specific features described individually or as part of an embodiment may be combined with other individually described features or as part of other embodiments. Therefore, elements and actions of the various embodiments described herein may be combined to provide additional embodiments. Thus, while certain exemplary embodiments of methods, apparatus, systems, and methods of manufacture and use thereof have been shown and described above, it should be clearly understood that the invention is not limited thereto, but may be embodied and practiced differently in other ways within the scope of the appended claims.

Claims

1. A method for analyzing secondary hydrogen concentration, the method comprising: A synthesis gas is produced that simulates a hydrogen fluid with a secondary hydrogen content of 0 mol%, such that the synthesis gas has a thermal conductivity equivalent to that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. The analyzer is calibrated using the synthesis gas as both the first and second calibration fluids during calibration. as well as After calibrating the analyzer, a reference gas is supplied to the analyzer, and a sample fluid of hydrogen fluid is supplied to the analyzer to determine the secondary hydrogen content and / or the positive hydrogen content of the sample.

2. The method according to claim 1, wherein the thermal conductivity of the synthesis gas is equal to the thermal conductivity of the hydrogen fluid having the 0 mol% secondary hydrogen content.

3. The method according to claim 1, wherein the thermal conductivity of the synthesis gas is within 0.5% of the thermal conductivity of the hydrogen fluid having a secondary hydrogen content of 0 mol%.

4. The method according to claim 1, wherein the thermal conductivity of the synthesis gas is within 0.1% of the thermal conductivity of the hydrogen fluid having a secondary hydrogen content of 0 mol%.

5. The method according to claim 1, wherein the analyzer is a thermal conductivity analyzer.

6. The method of claim 1, wherein the generation of the synthesis gas comprises: Hydrogen gas with a secondary hydrogen content of 25 mol% is mixed with helium gas to form the synthesis gas, such that the synthesis gas has a helium content between 0.5 mol% and 4 mol% helium, and the balance of the synthesis gas is the hydrogen gas with a secondary hydrogen content of 25 mol%.

7. The method according to claim 6, wherein the helium content of the synthesis gas is between 1.15 mol% helium and 1.30 mol% helium.

8. The method of claim 6, wherein the helium content of the synthesis gas is between 1.17 mol% helium and 1.27 mol% helium.

9. The method of claim 1, wherein the generation of the synthesis gas comprises: The synthesis gas is formed by mixing hydrogen gas with a secondary hydrogen content of 25 mol% with at least one additive fluid, wherein the at least one additive fluid includes one or more of nitrogen, krypton, argon, helium or combinations thereof.

10. The method of claim 1, wherein the generation of the synthesis gas comprises: Hydrogen is mixed with at least one additive fluid to form the synthesis gas.

11. A method for performing calibration of secondary hydrogen concentration analysis, the method comprising: A synthesis gas is produced that simulates a hydrogen fluid with a secondary hydrogen content of 0 mol%, such that the synthesis gas has a thermal conductivity equivalent to that of a hydrogen fluid with a secondary hydrogen content of 0 mol%. as well as The analyzer is calibrated using the synthesis gas as the first and second calibration fluids.

12. The method of claim 11, wherein calibrating the analyzer using the synthesis gas as the first calibration fluid and the second calibration fluid comprises: The first calibration fluid and reference fluid are supplied to the analyzer for being supplied to and / or through the measurement unit of the analyzer during a pre-selected equilibration period, in order to establish a first calibration data point for the analyzer. as well as After setting the first calibration point on the analyzer using the first calibration fluid, the supply of the first calibration fluid to the analyzer is stopped, and then the second calibration fluid and the reference fluid are supplied to the analyzer during a pre-selected balancing period to establish a second calibration data point for the analyzer.

13. The method of claim 12, wherein using the synthesis gas as the first calibration fluid and the second calibration fluid to calibrate the analyzer further comprises: Input is fed into the analyzer to define the secondary hydrogen content of 0 mol% secondary hydrogen for the first calibration fluid, while the first calibration fluid is supplied to the analyzer to establish the first calibration data point; as well as The input is fed into the analyzer to define the secondary hydrogen content of the second calibration fluid, while the second calibration fluid is supplied to the analyzer to establish the second calibration data point.

14. The method of claim 13, wherein the second calibration fluid is a hydrogen fluid, and the secondary hydrogen content of the second calibration fluid is 25 mol% secondary hydrogen.

15. The method of claim 11, wherein the generation of the synthesis gas comprises: Hydrogen gas with a secondary hydrogen content of 25 mol% is mixed with at least one additive fluid to form the synthesis gas.

16. The method of claim 15, wherein the at least one additive fluid comprises one or more of nitrogen, krypton, argon, helium, or combinations thereof.

17. The method of claim 16, wherein the helium content of the synthesis gas is between 1.15 mol% helium and 1.30 mol% helium.

18. The method of claim 16, wherein the helium content of the synthesis gas is between 1.17 mol% helium and 1.27 mol% helium.

19. An apparatus for analyzing secondary hydrogen concentration, the apparatus comprising: Analyzer; A reference gas source, which is fluidly connected to the analyzer; A first calibration gas source, which is fluidly connected to the analyzer, is a synthesis gas having a certain amount of hydrogen and at least one additive fluid to simulate a hydrogen fluid with a 0 mol% secondary hydrogen content, such that the synthesis gas has a thermal conductivity equivalent to that of a hydrogen fluid with a 0 mol% secondary hydrogen content. as well as A second calibration fluid source containing hydrogen, which is fluidly connected to the analyzer.

20. The apparatus of claim 19, wherein the thermal conductivity of the synthesis gas is within 1% of the thermal conductivity of the hydrogen fluid having a secondary hydrogen content of 0 mol%, and the analyzer is a thermal conductivity analyzer.

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